Display device and electronic apparatus

ABSTRACT

According to an aspect, a display device includes: a plurality of pixels aligned in row and column directions, each of the pixels including a drive element; a plurality of scan lines each coupled with the drive elements included in the pixels aligned in the row direction to transmit thereto a scan signal for selecting the pixels row by row; a plurality of signal lines each coupled with the drive elements included in the pixels aligned in the column direction to write display data; and a display control unit. The display control unit alternately repeats a display period and a stop period. In a latter term of the stop period, display control unit provides the display data written in the respective pixels in a row that has been selected during the display period immediately before the stop period, to the signal lines corresponding to the respective pixels.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application is a division application of U.S. patentapplication Ser. No. 14/179,903, filed on Feb. 13, 2014, whichapplication claims priority to Japanese Priority Patent Application JP2013-036408 filed in the Japan Patent Office on Feb. 26, 2013, theentire content of which is hereby incorporated by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to a display device and an electronicapparatus, and particularly to a display device and an electronicapparatus that have a stop period of stopping display between displayperiods.

2. Description of the Related Art

Recent years have seen increasing demands for display devices for use inmobile devices, such as mobile phones and electronic paper devices. Someof such display devices (such as one disclosed in Japanese PatentApplication Laid-open Publication No. 7-134278) include a display areaarranged with pixels in a matrix and switching elements provided foreach pixel, and are driven by an active matrix method.

Some of the display devices driven by the active matrix methodalternately repeat a display period of performing a display operation todisplay an image and a stop period of stopping the display operation.Such display devices may generate streak defects or unevenness in theimage caused by the display operation in the display period immediatelyafter the stop period.

For the foregoing reasons, there is a need for a display device and anelectronic apparatus that can suppress generation of streak defects orunevenness.

SUMMARY

According to an aspect, a display device that displays an imageincludes: a display area in which a plurality of pixels are aligned inrow and column directions, each of the pixels including a drive element;a plurality of scan lines extending in the row direction, each of thescan lines being coupled to the drive elements included in the pixelsaligned in the row direction to transmit thereto a scan signal forselecting the pixels in the display area row by row

a plurality of signal lines extending in the column direction, each ofthe signal lines being coupled to the drive elements included in thepixels aligned in the column direction to write display data of theimage to be displayed on the display area to the pixels in a rowselected by the scan signal; and a display control unit. The displaycontrol unit alternately repeats a display period of writing the displaydata to the pixels and a stop period of stopping the writing of thedisplay data to the pixels. In a former term of the stop period, thedisplay control unit sets all of the signal lines to have apredetermined potential. In a latter term of the stop period, displaycontrol unit provides the display data written in the respective pixelsin a row that has been selected during the display period immediatelybefore the stop period, to the signal lines corresponding to therespective pixels.

According to another aspect, a display device that displays an imageincludes: a display area in which a plurality of pixels are aligned inrow and column directions, each of the pixels including a drive element;a plurality of scan lines extending in the row direction, each of thescan lines being coupled to the drive elements included in the pixelsaligned in the row direction to transmit thereto a scan signal forselecting the pixels in the display area row by row; a plurality ofsignal lines extending in the column direction, each of the signal linesbeing coupled to the drive elements included in the pixels aligned inthe column direction to write display data of the image to be displayedon the display area to the pixels in a row selected by the scan signal;switches provided between a transmission source of the display data andthe signal lines; and a display control unit. The display control unitalternately repeats a display period of writing the display data to thepixels and a stop period of stopping the writing of the display data tothe pixels. In the stop period, the display control unit turns off allof the switches and sets wiring from the transmission source to theswitches to have any desirable potential.

According to another aspect, an electronic apparatus includes any one ofthe display devices.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram illustrating an example of a display deviceaccording to an embodiment;

FIG. 2 is a plan view illustrating the example of the display deviceaccording to the embodiment;

FIG. 3 is a sectional view illustrating an example of a liquid crystaldisplay unit according to the embodiment;

FIG. 4 is a block diagram illustrating the example of the liquid crystaldisplay unit according to the embodiment;

FIG. 5 is a diagram illustrating a pixel array of the liquid crystaldisplay unit according to the embodiment;

FIG. 6 is a schematic diagram for explaining a relation between a sourcedriver and signal lines in the display device according to theembodiment;

FIG. 7 is a timing chart for explaining an operation of the displaydevice according to the embodiment;

FIG. 8 is a diagram illustrating an example in which a display deviceaccording to a related art displays a gray raster image;

FIG. 9 is a timing chart illustrating the operation of the displaydevice according to the related art when displaying the gray rasterimage;

FIG. 10 is a diagram illustrating an example in which the display deviceaccording to the related art displays a black-and-gray image;

FIG. 11 is a timing chart illustrating the operation of the displaydevice according to the related art when displaying the black-and-grayimage;

FIG. 12 is a timing chart illustrating an example of control during astop period according to the embodiment;

FIG. 13 is a flowchart illustrating a procedure of the stop controlaccording to the embodiment;

FIG. 14 is a timing chart illustrating an example of stop controlaccording to a first modification of the embodiment;

FIG. 15 is a flowchart illustrating a procedure of the stop controlaccording to the first modification;

FIG. 16 is a timing chart illustrating an example of stop controlaccording to a second modification of the embodiment;

FIG. 17 is a diagram illustrating a chip on glass (COG), switches, andwiring coupling the COG with the switches;

FIG. 18 is a sectional view of the wiring coupling the COG with theswitches;

FIG. 19 is a flowchart illustrating the procedure of the stop controlaccording to the first modification;

FIG. 20 is a diagram illustrating an example of a display device with atouch detection function;

FIG. 21 is an explanatory diagram for explaining a basic principle ofcapacitative type touch detection, the diagram illustrating a state inwhich a finger is neither in contact with nor in proximity to a device;

FIG. 22 is an explanatory diagram illustrating an example of anequivalent circuit in the state illustrated in FIG. 21 in which thefinger is neither in contact with nor in proximity to a device;

FIG. 23 is an explanatory diagram for explaining the basic principle ofthe capacitative type touch detection, the diagram illustrating a statein which the finger is in contact with or in proximity to a device;

FIG. 24 is an explanatory diagram illustrating an example of theequivalent circuit in the state illustrated in FIG. 23 in which thefinger is in contact with or in proximity to a device;

FIG. 25 is a diagram illustrating an example of waveforms of a drivesignal and a touch detection signal;

FIG. 26 is a diagram illustrating an example of an electronic apparatusto which the display device according to the embodiment or any of themodifications thereof is applied;

FIG. 27 is a diagram illustrating an example of an electronic apparatusto which the display device according to the embodiment or any of themodifications thereof is applied;

FIG. 28 is a diagram illustrating the example of the electronicapparatus to which the display device according to the embodiment or anyof the modifications thereof is applied;

FIG. 29 is a diagram illustrating an example of an electronic apparatusto which the display device according to the embodiment or any of themodifications thereof is applied;

FIG. 30 is a diagram illustrating an example of an electronic apparatusto which the display device according to the embodiment or any of themodifications thereof is applied;

FIG. 31 is a diagram illustrating an example of an electronic apparatusto which the display device according to the embodiment or any of themodifications thereof is applied;

FIG. 32 is a diagram illustrating the example of the electronicapparatus to which the display device according to the embodiment or anyof the modifications thereof is applied;

FIG. 33 is a diagram illustrating the example of the electronicapparatus to which the display device according to the embodiment or anyof the modifications thereof is applied;

FIG. 34 is a diagram illustrating the example of the electronicapparatus to which the display device according to the embodiment or anyof the modifications thereof is applied;

FIG. 35 is a diagram illustrating the example of the electronicapparatus to which the display device according to the embodiment or anyof the modifications thereof is applied;

FIG. 36 is a diagram illustrating the example of the electronicapparatus to which the display device according to the embodiment or anyof the modifications thereof is applied;

FIG. 37 is a diagram illustrating the example of the electronicapparatus to which the display device according to the embodiment or anyof the modifications thereof is applied; and

FIG. 38 is a diagram illustrating an example of an electronic apparatusto which the display device according to the embodiment or any of themodifications thereof is applied.

DETAILED DESCRIPTION

Embodiments for practicing the present disclosure will be described indetail in the following order, with reference to the accompanyingdrawings.

1. Embodiment

-   -   1-1. Display device    -   1-2. Display device with touch detection function

2. Application examples (electronic apparatuses)

3. Aspects of present disclosure

1. Embodiment

A liquid crystal display device to which the present disclosure isapplied may be a display device for monochrome display or a displaydevice for color display. In a display device for color display, onepixel (unit pixel) serving as a unit of forming a color image includes aplurality of sub-pixels. More specifically, the unit pixel in thedisplay device for color display includes, for example, a total of threesub-pixels of a sub-pixel displaying red (R), a sub-pixel displayinggreen (G), and a sub-pixel displaying blue (B).

However, one pixel is not limited to the combination of the sub-pixelsof the three primary colors of R, G, and B. The unit pixel can beformed, for example, by adding a sub-pixel of one color or sub-pixels ofa plurality of colors to the sub-pixels of the three primary colors ofR, G, and B. More specifically, the unit pixel can be formed, forexample, by adding a sub-pixel displaying white (W) to increaseluminance, or by adding at least one sub-pixel displaying acomplementary color to expand a color reproduction range.

1-1. Display Device

FIG. 1 is a block diagram illustrating an example of the display deviceaccording to the present embodiment. The display device 1 includes aliquid crystal display unit 10 including liquid crystal display elementsas display elements, a control unit 11, a gate driver 12, a sourcedriver 13, a source selector 13S, and a drive electrode driver 14. Aswill be described later, the liquid crystal display unit 10 is a devicethat performs display by sequentially scanning one horizontal line at atime according to a scan signal Vscan fed from the gate driver 12. Thecontrol unit 11 serving as a display control unit of the display device1 is a circuit that feeds, based on an externally supplied video signalVdisp, control signals to the gate driver 12, the source driver 13, andthe drive electrode driver 14, and thus controls these drivers so as tooperate them in synchronization with each other. A control device in thepresent disclosure includes the control unit 11, the gate driver 12, thesource driver 13, and the drive electrode driver 14.

The gate driver 12 has a function to sequentially select, based on thecontrol signal transmitted from the control unit 11, one horizontal lineto be driven for display by the liquid crystal display unit 10. Thesource driver 13 is a circuit that feeds, based on the control signaltransmitted from the control unit 11, pixel signals Vpix to respectivepixels Pix (sub-pixels SPix) (to be described later) of the liquidcrystal display unit 10. In the present embodiment, each of the pixelsPix is the above-described unit pixel because the display device 1provides color display.

As will be described later, the source driver 13 generates, from thevideo signal Vdisp for one horizontal line, an image signal Vsigobtained by multiplexing the pixel signals Vpix of the sub-pixels SPixof the liquid crystal display unit 10, and transmits the image signalVsig to the source selector 13S. The source driver 13 also generatesselector switch control signals Vsel necessary for separating the pixelsignals Vpix multiplexed into the image signal Vsig from the imagesignal Vsig, and transmits the selector switch control signals Vseltogether with the image signal Vsig to the source selector 13S. Thismultiplexing can reduce the number of wiring lines between the sourcedriver 13 and the source selector 13S. In the present embodiment, thevideo signal Vdisp and the image signal Vsig correspond to display data.

The drive electrode driver 14 is a circuit that feeds, based on thecontrol signal transmitted from the control unit 11, a display drivingvoltage VCOM to common electrodes COML (to be described later) of theliquid crystal display unit 10.

FIG. 2 is a plan view illustrating the example of the display deviceaccording to the present embodiment. The liquid crystal display unit 10of the display device 1 includes a pixel substrate 2 (TFT substrate 21)and a counter substrate 3 (glass substrate 31) facing the pixelsubstrate 2. A flexible printed circuit board T is mounted on the liquidcrystal display unit 10. The pixel substrate 2 is equipped with a chipon glass (COG) 19. The pixel substrate 2 is provided with a display areaAd and frames Gd of the liquid crystal display unit 10. The COG 19 is achip of an integrated circuit (IC) driver mounted on the TFT substrate21, and is a control device having built-in circuits, such as thecontrol unit 11, necessary for display operations of the display device1. While the present embodiment forms the source driver 13 and thesource selector 13S described above on the TFT substrate 21, the presentdisclosure is not limited to such a structure. The source driver 13 andthe source selector 13S may be built into the COG 19. The gate driver 12is formed as gate drivers 12A and 12B on the TFT substrate 21. Thedisplay device 1 may have circuits including the gate driver 12 builtinto the COG 19. As illustrated in FIG. 2, the common electrodes COMLare provided in the display area Ad.

The source selector 13S is formed using thin-film transistor (TFT)elements near the display area Ad on a surface of the TFT substrate 21.A plurality of pixels are arranged in a matrix in the display area Ad.In the present embodiment, the row direction is the X-direction, and thecolumn direction is the Y-direction indicated in FIG. 2. The directionorthogonal to the X-direction and the Y-direction is the Z-direction.The Z-direction is orthogonal to the surface of the TFT substrate 21.The frames Gd and Gd are areas in which no pixels are arranged when thesurface of the TFT substrate 21 is viewed from a direction orthogonalthereto. The gate driver 12 is disposed at each of the frames Gd. Thegate driver 12 includes the gate drivers 12A and 12B, and is formedusing the TFT elements on the surface of the TFT substrate 21. The gatedrivers 12A and 12B can alternately drive the sub-pixels (pixels) fromone side in a direction (scan direction) in which the gate drivers 12Aand 12B are arranged with the display area Ad therebetween, in which thesub-pixels (pixels) are arranged in a matrix (to be described later).Alternatively, one scan line coupled to a plurality of sub-pixels(pixels) may be capable of being driven by both the gate drivers 12A and12B. The following description may refer to the gate driver 12A as a“first gate driver 12A” and the gate driver 12B as a “second gate driver12B”. The scan lines (to be described later) are arranged between thefirst gate driver 12A and the second gate driver 12B. The driveelectrode driver 14 applies the display driving voltage VCOM to thecommon electrodes COML via display wiring LDC.

Liquid Crystal Display Unit

FIG. 3 is a sectional view illustrating an example of the liquid crystaldisplay unit according to the present embodiment. FIG. 4 is a blockdiagram illustrating the example of the liquid crystal display unitaccording to the present embodiment. FIG. 5 is a diagram illustrating apixel array of the liquid crystal display unit according to the presentembodiment. As illustrated in FIG. 3, the liquid crystal display unit 10includes the pixel substrate 2, the counter substrate 3 disposed facinga surface of the pixel substrate 2 in a direction orthogonal thereto,and a liquid crystal layer 6 provided between the pixel substrate 2 andthe counter substrate 3.

The liquid crystal layer 6 modulates light passing therethroughaccording to the state of an electric field. In the present embodiment,the liquid crystal layer 6 contains liquid crystals of a horizontalelectric field mode, such as a fringe field switching (FFS) mode or anin-plane switching (IPS) mode, but, not limited to this, may containliquid crystals of a vertical electric field mode. Orientation film maybe provided between the liquid crystal layer 6 and the pixel substrate2, and between the liquid crystal layer 6 and the counter substrate 3,which are illustrated in FIG. 3, respectively.

The counter substrate 3 includes the glass substrate 31 and a colorfilter 33 formed on one surface of the glass substrate 31. A polarizingplate 35 is provided on the other surface of the glass substrate 31. Thepixel substrate 2 includes the TFT substrate 21 as a circuit substrate,a plurality of pixel electrodes 22 arranged in a matrix on the surfaceof the TFT substrate 21, the common electrodes COML formed between theTFT substrate 21 and the pixel electrodes 22, and an insulation layer 24insulating the pixel electrodes 22 from the common electrodes COML.

As illustrated in FIG. 4, the pixel substrate 2 includes, on the surfaceof the TFT substrate 21, the display area Ad, the COG 19 havingfunctions of an interface (I/F) and a timing generator, the first andthe second gate drivers 12A and 12B, and the source driver 13. Theflexible printed circuit board T illustrated in FIG. 2 transmitsexternal signals and drive power for driving the COG 19 to the COG 19illustrated in FIG. 4, which is disposed as the COG 19 illustrated inFIG. 2. The pixel substrate 2 includes the display area Ad, which lieson the surface of the TFT substrate 21 that is a transparent insulatingsubstrate (such as a glass substrate), and in which the pixels includingliquid crystal cells are arranged in a matrix. The pixel substrate 2also includes the source driver (a horizontal drive circuit) 13, thefirst gate driver 12A as a vertical drive circuit, and the second gatedriver 12B as a vertical drive circuit. The first and the second gatedrivers 12A and 12B are arranged with the display area Ad interposedtherebetween.

The display area Ad has a matrix structure in which the sub-pixels SPixeach including a liquid crystal layer are arranged in M rows by Ncolumns (M and N are natural numbers). The present application uses theterm “row” to refer to a pixel row including N sub-pixels SPix arrangedin one direction. Further, the present application uses the term“column” to refer to a pixel column including M sub-pixels SPix arrangedin a direction orthogonal to the direction of alignment of the row. Thevalues of M and N are determined according to display resolutions in thevertical and horizontal directions.

In the display area Ad, scan lines GCL_(i+1), GCL_(i+2), GCL_(i+3), . .. are wired for each row, and signal lines SGL_(j+1), SGL_(j+2),SGL_(j+3), SGL_(j+4), SGL_(j+5), . . . are wired for each column, withrespect to the array of M rows and N columns of the sub-pixels SPix.Hereinafter, in the embodiment, the scan lines GCL_(i+1), GCL_(i+2),GCL_(i+3), . . . may be represented as scan lines GCL or scan linesGCL_(i), and the signal lines SGL_(j+1), SGL_(j+2), SGL_(j+3),SGL_(j+4), SGL_(j+5), . . . may be represented as signal lines SGL orsignal lines SGL_(j). The scan lines GCL extend in the row direction,and the signal lines SGL extend in the column direction.

The pixel substrate 2 is externally supplied with external signals, thatis, a master clock, a horizontal synchronizing signal, and a verticalsynchronizing signal, which are in turn supplied to the COG 19. The COG19 converts the levels (increases the voltages) of the master clock, thehorizontal synchronizing signal, and the vertical synchronizing signalhaving the voltage amplitude of an external power supply to the voltageamplitude of an internal power supply required to drive the liquidcrystals, and passes the master clock, the horizontal synchronizingsignal, and the vertical synchronizing signal of the increased amplitudethrough the timing generator to generate a vertical start pulse VST, avertical clock pulse VCK, a switch control signal GCK, a horizontalstart pulse HST, and a horizontal clock pulse HCK. The COG 19 providesthe vertical start pulse VST, the vertical clock pulse VCK, and theswitch control signal GCK to the first and the second gate drivers 12Aand 12B, and provides the horizontal start pulse HST and the horizontalclock pulse HCK to the source driver 13. The COG 19 generates thedisplay driving voltage VCOM and provides it to the above-describedcommon electrodes COML. The display driving voltage VCOM is also calleda common potential because of being commonly provided to the respectivesub-pixels SPix with respect to the pixel electrodes.

Each of the first and the second gate drivers 12A and 12B includes atransfer circuit and a buffer circuit. The transfer circuit includes ashift register and may further include a latch circuit and so on. Eachof the first and the second gate drivers 12A and 12B generates verticalscan pulses as scan signals from the vertical start pulses VST and thevertical clock pulses VCK described above, and provides the generatedpulses to the scan lines GCL so as to sequentially select the sub-pixelsSPix row by row. The first and the second gate drivers 12A and 12B arearranged with the scan lines GCL interposed therebetween in theextending direction of the scan lines GCL. The first and the second gatedrivers 12A and 12B output the vertical scan pulses sequentially from arelatively upper side of the display area Ad toward a relatively lowerside of the display area Ad. The relatively upper side means the sideopposite to the COG 19, and the relatively lower side means the side ofthe COG 19.

The first and the second gate drivers 12A and 12B alternately apply thevertical scan pulses to the scan lines GCL in the direction (scandirection, or Y-direction) of alignment of the scan lines GCL, and thusselect the sub-pixels SPix of the display area Ad row by row. The firstand the second gate drivers 12A and 12B are arranged at the respectivelongitudinal ends of the scan lines GCL, and alternately apply thevertical scan pulses to the scan lines GCL in every other row, thusselecting the pixels of the display area Ad row by row. Each of the scanlines GCL is coupled to either one of the first and the second gatedrivers 12A and 12B at its end in the direction. This can reduce thenumber of transistor elements as compared with a case of coupling thegate drivers to longitudinal ends of each scan line GCL, respectively.As a result, the area of the above-described frames Gd can be reduced inthe display device 1.

The source driver 13 is supplied with, for example, a 6-bit display dataof red (R), green (G), and blue (B). The source driver 13 writes thedisplay data via the source selector 13S and the signal lines SGL to thesub-pixels SPix of the row selected through the vertical scan (scan inthe Y-direction) by the first or the second gate driver 12A or 12B,pixel by pixel, or a plurality of pixels at a time, or all pixels at atime.

The TFT substrate 21 is provided with the wiring, such as the signallines SGL that feed the pixel signals Vpix to the thin-film transistorsTr (hereinafter called TFT elements Tr as appropriate) of the sub-pixelsSPix illustrated in FIGS. 4 and 5 and to the pixel electrodes 22illustrated in FIG. 3, and the scan lines GCL that drive the TFTelements Tr. In this manner, the signal lines SGL extend in a planeparallel to the surface of the TFT substrate 21, and feed the pixelsignals Vpix for displaying an image to the pixels. The liquid crystaldisplay unit 10 illustrated in FIG. 5 includes the sub-pixels SPixarranged in a matrix. Each of the sub-pixels SPix includes the TFTelement Tr and a liquid crystal element LC. The TFT element Tr is ann-channel metal oxide semiconductor (MOS) TFT in the present example.One of the source and the drain of the TFT element Tr is coupled to oneof the signal lines SGL; the gate thereof is coupled to one of the scanlines GCL; and the other of the source and the drain is coupled to oneend of the liquid crystal element LC. The liquid crystal element LC iscoupled, for example, at one end thereof, to the drain of the TFTelement Tr, and at the other end thereof, to one of the commonelectrodes COML.

Each of the first and the second gate drivers 12A and 12B illustrated inFIG. 4 applies the vertical scan pulse to the gates of the TFT elementsTr of the sub-pixels SPix via the scan lines GCL illustrated in FIG. 5so as to sequentially select one row (one horizontal line) of thesub-pixels SPix formed in a matrix in the display area Ad as a row to bedriven for display. The source driver 13 feeds the pixel signals Vpixvia the signal lines SGL to the respective sub-pixels SPix included inone horizontal line sequentially selected by the first and the secondgate drivers 12A and 12B. These sub-pixels SPix perform display of onehorizontal line according to the supplied pixel signals Vpix. The driveelectrode driver 14 applies the drive signal for display (displaydriving voltage VCOM) to the common electrodes COML.

As described above, in the display device 1, the first and the secondgate drivers 12A and 12B drive the scan lines GCL_(i+i), GCL_(i+2),GCL_(i+3), . . . to perform sequential scan, and thereby sequentiallyselect one horizontal line. The source driver 13 feeds the pixel signalsVpix to the sub-pixels SPix belonging to one horizontal line, so thatthe display device 1 performs display one horizontal line at a time.When this display operation is performed, the drive electrode driver 14applies the display driving voltage VCOM to the common electrodes COML.

Color regions of the color filter 33 illustrated in FIG. 3 that arecolored, for example, in the three colors of red (R), green (G), andblue (B) are periodically arranged, and one set of these color regions32R, 32G, and 32B (refer to FIG. 5) of the three colors of R, G, and Bis associated, as a pixel Pix, with the sub-pixels SPix illustrated inFIG. 5 mentioned above. The color filter 33 faces the liquid crystallayer 6 in the direction orthogonal to the TFT substrate 21. This allowseach of the sub-pixels SPix to display a single color. The color filter33 may have a combination of other colors if colored in differentcolors. The color filter 33 is not necessarily provided. Thus, a regionfree from the color filter 33, that is, a region of transparentsub-pixels SPix may exist.

The sub-pixels SPix illustrated in FIG. 5 are coupled to the othersub-pixels SPix belonging to the same row of the liquid crystal displayunit 10 via the corresponding scan line GCL. The scan lines GCL arecoupled to the gate driver 12, and supplied with the scan signals Vscanfrom the gate driver 12. The sub-pixels SPix are coupled to the othersub-pixels SPix belonging to the same column of the liquid crystaldisplay unit 10 via the corresponding signal line SGL. The signal linesSGL are coupled to the source driver 13, and supplied with the pixelsignals Vpix from the source driver 13.

FIG. 6 is a schematic diagram for explaining a relation between thesource driver and the signal lines in the display device according tothe present embodiment. As illustrated in FIG. 6, the signal lines SGLof the display device 1 are coupled to the source driver 13 via thesource selector 13S. The source selector 13S performs on/off operationsaccording to the selector switch control signals Vsel.

As illustrated in FIG. 6, based on the display data and the sourcedriver control signal fed from the control unit 11, the source driver 13generates and outputs the image signal. From the display data for onehorizontal line, the source driver 13 generates the image signals Vsiginto each of which the pixel signals Vpix (VpixR, VpixG, and VpixB) tobe provided to a plurality of sub-pixels SPix (three sub-pixels SPix inthe present example) are multiplexed, and provides the image signalsVsig to the source selector 13S. The source driver 13 also generates theselector switch control signals Vsel (VselR, VselG, and VselB) necessaryfor separating the pixel signals VpixR, VpixG, and VpixB from each imagesignal Vsig into which the pixel signals VpixR, VpixG, and VpixB havebeen multiplexed, and provides the generated signals Vsel together withthe image signals Vsig to the source selector 13S. This multiplexingreduces the number of wiring lines between the source driver 13 and thesource selector 13S as described above.

Based on the image signals Vsig as display data and the selector switchcontrol signals Vsel provided by the source driver 13, the sourceselector 13S separates the pixel signals Vpix from each image signalVsig into which the pixel signals Vpix have been time-divisionallymultiplexed, and provides the pixel signals Vpix to the liquid crystaldisplay unit 10 of the display device 1. The source selector 13Sincludes, for example, three switches SWR, SWG, and SWB. One end of eachof the three switches SWR, SWG, and SWB is coupled with each other, andsupplied with the image signal Vsig from the source driver 13. The otherend of each of the three switches SWR, SWG, and SWB is coupled to thesub-pixels SPix via the corresponding signal line SGL of the liquidcrystal display unit 10.

The control unit 11 provides the signal for display to the source driver13. Based on the signal, the source driver 13 generates the selectorswitch control signals Vsel (VselR, VselG, and VselB). The selectorswitch control signals Vsel (VselR, VselG, and VselB) provided by thesource driver 13 open or close the three switches SWR, SWG, and SWB,respectively. Such a structure allows the source selector 13S tosequentially turn on the switches SWR, SWG, and SWB on a time-divisionbasis according to the selector switch control signals Vsel. The sourceselector 13S performs such an operation to separate the pixel signalsVpix (VpixR, VpixG, and VpixB) as display data from the multiplexedimage signal Vsig as display data. The source selector 13S feeds thepixel signals Vpix to the respective three sub-pixels SPix.

The above-described color regions 32R, 32G, and 32B colored in the threecolors of red (R), green (G), and blue (B) correspond to the respectivesub-pixels SPix. With this configuration, the pixel signal VpixR isprovided to the sub-pixel SPix corresponding to the color region 32R,the pixel signal VpixG is provided to the sub-pixel SPix correspondingto the color region 32G, and the pixel signal VpixB is provided to thesub-pixel SPix corresponding to the color region 32B.

The sub-pixels SPix are coupled with the other sub-pixels SPix belongingto the same column of the liquid crystal display unit 10 via thecorresponding common electrode COML. The common electrodes COML arecoupled with the drive electrode driver 14, and supplied with thedisplay driving voltage VCOM from the drive electrode driver 14. Inother words, in the present example, the sub-pixels SPix belonging tothe same column share the common electrode COML.

Operation of Display Device

FIG. 7 is a timing chart for explaining an operation of the displaydevice according to the present embodiment. The display device 1alternately repeats a period (display period) TI in which display driveis performed and a period (stop period) TR in which display drive isstopped, during one frame period of the liquid crystal display unit 10.Specifically, during (i+1) of the display period TI, the switches SWR,SWG, and SWB of the source selector 13S illustrated in FIG. 6 aresequentially turned on and off, and thus, the pixel signals Vpix (VpixR,VpixG, and VpixB) are provided to the respective sub-pixels SPix coupledto the scan line GCL_(i+1) illustrated in FIG. 4. In other words, thedisplay data is written to the sub-pixels SPix coupled to the scan lineGCL_(i+1). During (i+2) of the display period TI, the switches SWR, SWG,and SWB operate in the same manner as during (i+1) of the display periodTI, and thus, the pixel signals Vpix (VpixR, VpixG, and VpixB) areprovided to the respective sub-pixels SPix coupled to the scan lineGCL_(i+2) illustrated in FIG. 4, so that the display data is written tothe sub-pixels SPix.

The stop period TR is provided after the end of (i+2) of the displayperiod TI before (i+3) of the display period TI. The present examplemaintains all of the switches SWR, SWG, and SWB of the source selector13S illustrated in FIG. 6 in the on state during the stop period TR. Thestop period TR is a state in which the gate driver 12 illustrated inFIG. 4 does not select any of the scan lines GCL. Thus, the stop periodTR is a period in which the drive for display is stopped, or, morespecifically, a period in which the operation of writing the displaydata is stopped for any of the scan lines GCL. For example, a drivedifferent from the drive for displaying an image can be performed duringthe stop period TR. Examples of such a drive include, but are notlimited to, a drive in which the potential of the common electrodes COMLchanges, including, as an example, a sensing drive of a touch panel.After the stop period TR, the display period TI is started again as(i+3). The display device 1 performs display of one frame of the liquidcrystal display unit 10 while alternately repeating the display periodTI and the stop period TR. A description will be made of an imagedisplayed on the display area Ad of the display device 1 when theoperation of repeating the display period TI and the stop period TR isperformed during one frame.

Images Displayed in Display Area

FIG. 8 is a diagram illustrating an example in which a display deviceaccording to a related art displays a gray raster image. FIG. 9 is atiming chart illustrating the operation of the display device accordingto the related art when displaying the gray raster image. As illustratedin FIG. 8, the display device according to the related art displays theimage using a column inversion method. The gray raster image is an imagein which every sub-pixel is displayed at a certain gradation level. InFIGS. 8 and 9, the symbol Even corresponds to even-numbered scan linesGCL, and the symbol Odd corresponds to odd-numbered scan lines GCL. Thesymbols n and q are natural numbers, and are used for identifying thescan lines GCL and the signal lines SGL. The symbols k+1 and k+2attached to the display period TI and the stop period TR are used foridentifying these periods. The symbol k is a natural number. The symbolsR, G, and B attached to the signal lines SGL represent the colors of thesub-pixels SPix coupled to the signal lines SGL. The symbols n−1 and nare used for identifying the signal lines SGL. The symbol n is a naturalnumber.

In the example illustrated in FIGS. 8 and 9, during a display periodTI_k+1, a driver similar to the gate driver 12 illustrated in FIG. 4selects the scan lines GCL in the order of Even_q, Odd_q+1, andEven_q+1. When each of the scan lines GCL corresponding to Even_q,Odd_q+1, and Even_q+1 is selected, the switches SWR, SWG, and SWB of aselector similar to the source selector 13S illustrated in FIG. 6 aresequentially turned on and off, and thus, the pixel signals Vpix (VpixR,VpixG, and VpixB) are provided to the respective sub-pixels SPix coupledto the selected scan line GCL so as to write the display data to therespective sub-pixels SPix.

During a stop period TR_k+1, the switches SWR, SWG, and SWB aremaintained at ON (H). This causes the signal lines SGL to be coupled toground, and thus causes all potentials of the signal lines SGL_Bn−1,SGL_Rn, SGL_Gn, and SGL_Bn to be 0 during the stop period TR_k+1.

During a display period TI_k+2 following the stop period TR_k+1, theswitches SWR, SWG, and SWB are sequentially turned on and off, and thus,the pixel signals Vpix (VpixR, VpixG, and VpixB) are provided to therespective sub-pixels SPix coupled to the selected scan line GCL so asto write the display data to the respective sub-pixels SPix. In thepresent example, the scan line GCL corresponding to Odd_q+2 is selectedat the beginning of the display period TI_k+2. Turning on and off of theswitch SWR writes the pixel signal VpixR as display data to the signalline SGL_Rn (symbol WR1 in FIG. 9). In the present example, thepotential of the signal line SGL_Rn turns from 0 to H. The pixel signalVpixG is written as display data to the signal line SGL_Gn (symbol WR2in FIG. 9). This turns the potential of the signal line SGL_Rn from 0 toL in the present example. The pixel signal VpixB is written as displaydata to the signal lines SGL_Bn−1 and SGL_Bn (symbols WR3 a and WR3 b inFIG. 9). This turns the potential of the signal line SGL_Bn−1 from 0 toL and the potential of the signal line SGL_Bn from 0 to H in the presentexample.

When the scan line GCL is switched during the display period TI_k+1, thesignal lines SGL_Bn−1, SGL_Rn, SGL_Gn, and SGL_Bn maintain display dataimmediately before the scan line GCL is switched. However, thepotentials of the signal lines SGL_Bn−1, SGL_Rn, SGL_Gn, and SGL_Bn areturned to 0 during the stop period TR_k+1. Therefore, in a rowcorresponding to Odd_q+2 selected at the beginning of the display periodTI_k+2 immediately after the stop period TR_k+1, the signal linesSGL_Bn−1, SGL_Rn, SGL_Gn, and SGL_Bn receive new display data from thestate during the stop period TR_k+1, that is, from the state in whichthe potentials are 0. As a result, the potential changes in the signallines SGL when a scan line GCL is first selected immediately after thetransition from the stop period TR_k+1 to the display period TI_k+2differ from the potential changes in the signal lines SGL during thedisplay period TI_k+1.

In the present example, only in a row corresponding to Odd_q+2, theadjacent signal lines SGL (specifically, the signal lines SGL_Bn−1 andSGL_Rn, the signal lines SGL_Rn and SGL_Gn, and the signal lines SGL_Gnand SGL_Bn) are peculiarly coupled with each other by electrostaticcapacitance (CP1, CP2, and CP3 in FIG. 9). This results in differencesin potential of the sub-pixels SPix between the sub-pixels SPix of a rowcorresponding to Odd_q+2 and the sub-pixels SPix of the other rows, eachof which are supposed to display the same gradation.

In the example illustrated in FIG. 9, the dotted lines representing thepotentials of the sub-pixels SPixR and SPixG indicate the potentials ina row corresponding to Odd_q+2, and the solid lines representing thepotentials of the sub-pixels SPixR and SPixG indicate the potentials inthe other rows. The above-described phenomenon causes potentialdifferences ΔVr and ΔVg between a row corresponding to Odd_q+2 and theother rows. The potential differences ΔVr and ΔVg can generate, forexample, streak defects or unevenness between the sub-pixels SPix of arow corresponding to Odd_q+2 and the sub-pixels SPix of other rowsadjacent thereto. The same applies to cases in which the display device1 displays an image other than the gray raster image.

FIG. 10 is a diagram illustrating an example in which the display deviceaccording to the related art displays a black-and-gray image. FIG. 11 isa timing chart illustrating the operation of the display deviceaccording to the related art when displaying the black-and-gray image.The black-and-gray image has sub-pixels displayed in black in a zigzagpattern. In the case of the black-and-gray image, the potentials of thesignal lines SGL_Bn−1, SGL_Rn, SGL_Gn, and SGL_Bn are also turned to 0during the stop period TR_k+1. Therefore, the potential changes in thesignal lines SGL when a scan line GCL is first selected immediatelyafter the transition from the stop period TR_k+1 to the display periodTI_k+2 differ from the potential changes in the signal lines SGL duringthe display period TI_k+1, as illustrated in FIG. 11.

Also in the present example, only in a row corresponding to Odd_q+2, theadjacent signal lines SGL are peculiarly coupled with each other by theelectrostatic capacitance. This results in differences in potential ofthe sub-pixels SPix between the sub-pixels SPix of a row correspondingto Odd_q+2 and the sub-pixels SPix of the other rows, each of which thatare supposed to display the same gradation. In the example illustratedin FIG. 11, the dotted line representing the potential of the sub-pixelSPixG indicates the potential in a row corresponding to Odd_q+2, and thesolid line representing the potential of the sub-pixel SPixG indicatesthe potential in the other rows. The potential difference ΔVg caused bythe above-described phenomenon can generate, for example, the streakdefects or the unevenness between the sub-pixels SPix of a rowcorresponding to Odd_q+2 and the sub-pixels SPix of other rows adjacentthereto.

Control According to Present Embodiment

To reduce the generation of, for example, the streak defects or theunevenness when alternately repeating the display period TI and the stopperiod TR during one frame period, the display device 1 performs controlso that the potential changes in the signal lines SGL immediately afterthe transition from a stop period TR to a display period TI are equal tothe potential changes in the signal lines SGL during a display period TIbefore the stop period TR. A description will be made of the control ofthe display device 1 during the stop period TR, more specifically, thecontrol performed by the control unit 11 as the display control unit,the source driver 13, etc.

FIG. 12 is a timing chart illustrating an example of the control duringthe stop period according to the present embodiment. In the controlduring the stop period (hereinafter called “stop control” asappropriate) according to the present embodiment, the display controlunit sets all of the signal lines SGL to have a predetermined potentialduring the former term of the stop period TR. On the other hand, duringthe latter term of the stop period TR, the display control unit suppliesthe pixel signals Vpix written to the respective sub-pixels SPixincluded in a row that has been selected during the last one horizontalscanning period 1H in the display period TI immediately before the stopperiod TR to the signal lines SGL corresponding to the respectivesub-pixels SPix. Controlling in this way equalizes the potential changesin the signal lines SGL immediately after the transition from a stopperiod TR to a display period TI to the potential changes in the signallines SGL during a display period TI before the stop period TR. This canreduce, for example, the streak defects or the unevenness generatedbetween the sub-pixels SPix of a row first selected immediately afterthe transition from the stop period TR to the display period TI and thesub-pixels SPix of other rows.

The numbers and m (m is a natural number of 2 or more) attached to thesymbols SGL and P in FIG. 12 (and similar figures below) are used foridentifying the type of colors displayed by the display device 1. Forexample, m=3 when the display device 1 displays the three colors of R,G, and B, and m=4 when the display device 1 displays the three colors ofR, G, and B and an additional color white (W). The symbol P in FIG. 12represents display data written to the sub-pixels SPix. Each of P1, P2,. . . , and Pm represents display data written to each of the sub-pixelsSPix, and corresponds to, for example, the pixel signal Vpix. Thedisplay control device of the display device 1 drives each of thesub-pixels SPix included in one pixel on a time-division basis. In otherwords, the display data P is written in the order of P1, P2, . . . , andPm to the corresponding sub-pixels SPix.

In the stop control according to the present embodiment, the stop periodTR_k+1 is divided into a former term Term1 and a latter term Term2, asillustrated in FIG. 12. In the present embodiment, a transition from thedisplay period TI_k+1 to the stop period TR_k+1 causes the displaycontrol unit to turn on all switches SW1, SW2, . . . , and SWm. Whenm=3, the switches SW1, SW2, . . . , and SWm correspond to the switchesSWR, SWG, and SWB included in the source selector 13S illustrated inFIG. 6.

After all of the switches SW1, SW2, . . . , and SWm are turned on, thedisplay control unit, more specifically, the control unit 11 illustratedin FIG. 1, sets all signal lines SGL1, SGL2, . . . , and SGLm coupled tothe switches SW1, SW2, . . . , and SWm, respectively, to have thepredetermined potential (charges all the signal lines to have thepredetermined potential) via the source driver 13. The potential mayhave any value. The control unit 11 turns off all of the switches SW1,SW2, . . . , and SWm immediately before the end of the former term Term1of the stop period TR_k+1. When the latter term Term2 of the stop periodTR_k+1 begins, the control unit 11 illustrated in FIG. 1 supplies thesignal lines SGL1, SGL2, . . . , and SGLm corresponding to therespective pixels (sub-pixels SPix), via the source driver 13, with thedisplay data P1, P2, . . . , and Pm written to the respective pixels(sub-pixels SPix) included in a row that has been selected during thelast one horizontal scanning period 1H in the display period TI_k+1immediately before the stop period TR_k+1.

The display data P1, P2, . . . , and Pm written to the respective signallines SGL in the latter term Term2 are the display data P1, P2, . . . ,and Pm that have been written in the respective sub-pixels SPix duringone horizontal scanning period 1H immediately before the stop periodTR_k+1. One horizontal scanning period 1H corresponds to a time in whichthe pieces of display data are written to the sub-pixels SPix of onehorizontal line coupled to the scan line GCL selected by the gate driver12 illustrated in FIG. 2. After the end of the display period TI_k+1,the control unit 11 temporarily stores the display data P1, P2, . . . ,and Pm, for example, in a storage unit. Then, in the latter term Term2,the control unit 11 sequentially turns on the switches SW1, SW2, . . . ,and SWm while sequentially reading the display data P1, P2, . . . , andPm from the storage unit mentioned above so as to write the display datato the corresponding signal lines SGL (charge the signal lines SGL).After the transition from the stop period TR_k+1 to the next displayperiod TI_k+2, the control unit 11 drives the gate driver 12 and thesource driver 13 to perform display of the remaining horizontal lines(the scan lines GCL and groups of the sub-pixels SPix coupled thereto).

In the latter term Term2, the display device 1 writes the display dataP1, P2, . . . , and Pm that have been displayed during one horizontalscanning period 1H immediately before the stop period TR_k+1 to thecorresponding signal lines SGL. This allows the display device 1 tosubstantially equalize the potential changes in the signal lines SGLimmediately after the transition from the stop period TR_k+1 to thedisplay period TI_k+2 to the potential changes in the signal lines SGLduring the display period TI before the stop period TR. This allows thedisplay device 1 to reduce, for example, the streak defects or theunevenness generated between the sub-pixels SPix of a row first selectedimmediately after the transition from the stop period TR_k+1 to thedisplay period TI_k+2 and the sub-pixels SPix of other rows.

The display device 1 turns on all of the switches SW1, SW2, . . . , andSWm in the former term Term1, and can thereby set all of the signallines SGL coupled thereto to have any desirable potential. For example,fixing the potential of all of the signal lines SGL to a predeterminedvalue during the former term Term1 desirably improves resistance todisturbance noise. The time of keeping on all of the switches SW1, SW2,. . . , and SWm in the former term Term1 is preferably, but not limitedto be, longer from the viewpoint of improving the resistance todisturbance noise.

The control unit 11 writes the display data P1, P2, . . . , and Pm thathave been displayed during the last one horizontal scanning period 1H tothe corresponding signal lines SGL. This allows the driving method, thatis, the on-off timing, of the switches SW1, SW2, . . . , and SWm in thelatter term Term2 to be the same as that in the display periods TI_k+1,TI_k+2, etc. This can minimize additions and changes in the logic of thecontrol unit 11.

In the latter term Term2 of the stop period TR, the display controlunit, more specifically, the control unit 11 may eliminate providing thedisplay data P to the signal line SGL corresponding to a pixel Pix(specifically, sub-pixels SPix included in the pixels Pix) to which thedisplay data is written first, among the pixels a row selected by thegate driver 12. In the present example, the display data P1 is firstwritten to the sub-pixel SPix corresponding to the signal line SGL1,among the sub-pixels SPix included in the pixels Pix. For example, thepixel Pix includes SPixR, SPixG, and SPixB for displaying R, G, and B,respectively, as sub-pixels, and the display data P is first written tothe sub-pixel SPixR for displaying R.

In the latter term Term2 of the stop period TR_k+1, the control unit 11does not write the display data P1 that has been displayed during onehorizontal scanning period 1H immediately before the stop period TR_k+1to the signal line SGL1. The signal line SGL1 coupled to the pixel(sub-pixel coupled to the signal line SGL1 in the present example) towhich the display data P is written first is not affected by potentialchanges in the signal lines SGL2, . . . , and SGLm coupled with theother sub-pixels if the potential changes in those signal lines are thesame between the display periods TI_k+1 and TI_k+2 before and after thestop period TR_k+1. In the latter term Term2 of the stop period TR_k+1,the control unit 11 can eliminate providing the display data P to thesignal line SGL to which the display data P is written first, and thusonly need to write the display data P to the (m−1) signal lines SGL inthe latter term Term2 for each pixel Pix. This results in shortening thelatter term Term2 of the display device 1. A procedure of the stopcontrol according to the present embodiment will be briefly described.

FIG. 13 is a flowchart illustrating the procedure of the stop controlaccording to the present embodiment. To perform the stop controlaccording to the present embodiment, the display control unit, morespecifically, the control unit 11 of the display device 1 drives displayof the liquid crystal display unit 10 included in the display device 1at Step S101. Then, the control unit 11 performs the process at StepS102, and, if the process is in the stop period TR (Yes at Step S102),the control unit 11 performs processing of Step S103. If the process isnot in the stop period TR (No at Step S102), the control unit 11 returnsto the start and performs the processes from Step S101.

At Step S103, the control unit 11 turns on all of the switches SW1, SW2,. . . , and SWm, and then charges all of the signal lines SGL1, SGL2, .. . , and SGLm coupled to the respective switches SW1, SW2, . . . , andSWm to have the predetermined potential via the source driver 13. Then,the control unit 11 performs the process at Step S104, and, if theformer term Term1 has elapsed (Yes at Step S104), the control unit 11performs the process at Step S105. If the former term Term1 has notelapsed (No at Step S104), the control unit 11 repeats the processes atSteps S103 and S104.

Step S105 is the process of the latter term Term2 of the stop period TR.The control unit 11 provides the display data P1, P2, . . . , and Pmwritten to the respective sub-pixels SPix in a row that has beenselected during the last one horizontal scanning period 1H in thedisplay period TI immediately before the stop period TR to the signallines SGL1, SGL2, . . . , and SGLm corresponding to the respectivesub-pixels SPix. If the latter term Term2 has not elapsed (No at StepS106), the control unit 11 repeats Steps S105 and S106. If the latterterm Term2 has elapsed (Yes at Step S106), the control unit 11 returnsto the start and performs the processes from Step S101. Performing theseprocesses allows the control unit 11 to reduce, for example, the streakdefects or the unevenness generated in the display area Ad of the liquidcrystal display unit 10 of the display device 1.

First Modification

In the former term Term1 of the stop period TR, stop control accordingto a first modification of the embodiment supplies the signal lines SGLwith the respective pieces of the display data P that have been writtenin any pixel (sub-pixel SPix) except the pixel (sub-pixel SPix) to whichthe display data P is written first, among the respective pixels(respective sub-pixels SPix) in a row that has been selected during thelast one horizontal scanning period 1H in the last display period TI. Inthe latter term Term2 of the stop period TR, the stop control accordingto the first modification provides, among the pieces of display data Pwritten in the respective pixels (respective sub-pixels SPix) in a rowthat has been selected during the last one horizontal scanning period 1Hin the last display period TI, display data other than the display dataP that has been written in the pixel (sub-pixel SPix) to which thedisplay data P is written first and the display data P that has beengiven to the signal lines SGL in the former term Term1 of the stopperiod TR, to the signal line SGL corresponding to the pixel (sub-pixelSPix) in which the display data has been written. Controlling in thisway can reduce, for example, the streak defects or the unevenness, andcan also shorten the time of the latter term Term2 of the stop periodTR.

FIG. 14 is a timing chart illustrating an example of the stop controlaccording to the first modification. In the stop control according tothe first modification, the transition from the display period TI_k+1 tothe stop period TR_k+1 causes the display control unit, morespecifically, the control unit 11 to turn on all of the switches SW1,SW2, . . . , and SWm. After turning on all of the switches SW1, SW2, . .. , and SWm, the control unit 11 provides the display data P3 via thesource driver 13 to all of the signal lines SGL1, SGL2, . . . , and SGLmcoupled to the respective switches SW1, SW2, . . . , and SWm. Thedisplay data P3 has been written in any one of the sub-pixels SPixexcept the sub-pixel SPix to which the display data P1 is written first,among the sub-pixels SPix in a row that has been selected during thelast one horizontal scanning period 1H in the last display periodTI_k+1. In the present example, the display data P1 is first written tothe sub-pixel SPix corresponding to the signal line SGL1, among thesub-pixels SPix included in the pixels Pix. In the former term Term1,all of the signal lines SGL1, SGL2, . . . , and SGLm only need to begiven any of the display data P2, P3, . . . , and Pm that have beenwritten in the sub-pixels SPix except the sub-pixel SPix correspondingto the signal line SGL1 to which the display data P1 is written first,among the sub-pixels SPix corresponding to the signal lines SGL1, SGL2,SGL3, . . . , and SGLm.

The control unit 11 turns off all of the switches SW1, SW2, . . . , andSWm immediately before the end of the former term Term1 of the stopperiod TR_k+1. When the latter term Term2 of the stop period TR_k+1begins, the control unit 11 provides the display data P2, . . . , Pmobtained by excluding the display data P1 and P3 from the display dataP1, P2, P3, . . . , and Pm to the corresponding signal lines SGL2, . . ., and SGLm via the source driver 13. In other words, the signal linesSGL2, . . . , and SGLm are supplied with the display data P2, . . . ,and Pm excluding the display data P1 that has been written in thesub-pixel SPix to which the display data P is written first and thedisplay data P3 that has been written to the signal lines SGL1, SGL2,SGL3, . . . , and SGLm in the former term Term1. In the latter termTerm2 of the stop period TR_k+1, the display data P2, . . . , and Pm arenot written to the signal line SGL to which the display data P1 iswritten first and the signal line SGL corresponding to the display dataP3 that has been written to the signal lines SGL1, SGL2, SGL3, . . . ,and SGLm in the former term Term1. During the latter term Term2, thesesignal lines SGL are held to maintain the display data P3 written in theformer term Term1.

The display data P3 written to the sub-pixels SPix in the former termTerm1 is any of the display data P1, P2, . . . , and Pm that have beenwritten in the sub-pixels SPix during one horizontal scanning period 1Himmediately before the stop period TR_k+1 except the display data P1. Inthe latter term Term2, the display data P2, . . . , and Pm during onehorizontal scanning period 1H immediately before the stop period TR_k+1are written to the sub-pixels SPix to which the pieces of display dataexcept the display data P1 and P3 have been written during onehorizontal scanning period 1H immediately before the stop period TR_k+1.

After the end of the display period TI_k+1, the control unit 11temporarily stores the display data P2, P3, . . . , and Pm excluding thedisplay data P1 during the last one horizontal scanning period 1H, forexample, in the storage unit. Then, in the former term Term1, thecontrol unit 11 reads the display data P3 from the storage unit, andwrites the display data P3 to all of the signal lines SGL (charges thesignal lines SGL). In the latter term Term2, the control unit 11sequentially reads the display data P2, . . . , and Pm excluding thedisplay data P3 from the storage unit, and writes the display data P2, .. . , and Pm to the corresponding signal lines SGL (charges the signallines SGL). After the transition from the stop period TR_k+1 to the nextdisplay period TI_k+2, the control unit 11 drives the gate driver 12 andthe source driver 13 to perform display of the remaining horizontallines (the scan lines GCL and groups of the sub-pixels SPix coupledthereto).

The stop control as described above causes the display device 1 towrite, during the latter term Term2, the display data P2, . . . , and Pmthat have been displayed during one horizontal scanning period 1Himmediately before the stop period TR_k+1 to the signal lines SGL exceptthe signal line SGL1 to which the display data P1 is written first andthe signal line SGL3 originally corresponding to the display data P3that has been written to the signal lines SGL during the former termTerm1. Any one of the pieces of display data P2, P3, . . . , and Pm iswritten to the signal line to which the display data P1 is writtenfirst. This allows the display device 1 to substantially equalize thepotential changes in the signal lines SGL immediately after thetransition from the stop period TR_k+1 to the display period TI_k+2 tothe potential changes in the signal lines SGL during the display periodTI before the stop period TR. This allows the display device 1 toreduce, for example, the streak defects or the unevenness generatedbetween the sub-pixels SPix of a row first selected immediately afterthe transition from the stop period TR_k+1 to the display period TI_k+2and the sub-pixels SPix of other rows.

In the former term Term1, the display device 1 turns on all of theswitches SW1, SW2, . . . , and SWm, and writes the display data P3 toall of the signal lines SGL1, SGL2, SGL3, . . . , and SGLm, therebyfixing all of the signal lines SGL1, SGL2, SGL3, . . . , and SGLm to thepredetermined potential. This improves the resistance of the displaydevice 1 to disturbance noise. The first modification only needs towrite the display data P to the (m−2) signal lines SGL for each pixelPix in the latter term Term2, and thus can shorten the latter termTerm2. A procedure of the stop control according to the firstmodification will be briefly described.

FIG. 15 is a flowchart illustrating the procedure of the stop controlaccording to the first modification. Steps S201 to S203 of the stopcontrol according to the first modification are the same as Steps S101to S103 of the above-described stop control, and thus descriptionthereof will not be repeated. At Step S204, the control unit 11 providesdisplay data other than P1 (the display data P3 in the present example)via the source driver 13 to all of the signal lines SGL1, SGL2, . . . ,and SGLm coupled to the respective switches SW1, SW2, . . . , and SWm.The control unit 11 performs the process at Step S205, and, if theformer term Term1 has elapsed (Yes at Step S205), the control unit 11performs the process at Step S206. If the former term Term1 has notelapsed (No at Step S205), the control unit 11 repeats the processes atSteps S203 to S205.

Step S206 is the process of the latter term Term2 of the stop period TR.The control unit 11 provides the display data P2, . . . , and Pmexcluding the display data P1 and the display data P3 that has beenwritten to all of the signal lines SGL during the former term Term1 tothe corresponding signal lines SGL2, . . . , and SGLm. If the latterterm Term2 has not elapsed (No at Step S207), the control unit 11repeats Steps S206 and S207. If the latter term Term2 has elapsed (Yesat Step S207), the control unit 11 returns to the start and performs theprocesses from Step S201. Performing these processes allows the controlunit 11 to reduce, for example, the streak defects or the unevennessgenerated in the display area Ad of the liquid crystal display unit 10of the display device 1.

Second Modification

During the stop period TR, stop control according to a secondmodification of the embodiment turns off all of the switches, and setsthe wiring from a transmission source of the display data to theswitches to have any desirable potential.

FIG. 16 is a timing chart illustrating an example of the stop controlaccording to the second modification. FIG. 17 is a diagram illustratingthe COG, the switches, and the wiring coupling the COG with theswitches. FIG. 18 is a sectional view of the wiring coupling the COGwith the switches. In the stop control according to the secondmodification, the display control unit, more specifically, the controlunit 11 illustrated in FIG. 1, turns off all of the switches SW1, SW2, .. . , and SWm during the stop period TR_k+1. Controlling in this wayplaces the signal lines SGL1, SGL2, . . . , and SGLm coupled to therespective switches SW1, SW2, . . . , and SWm in a state of highimpedance, and thus holds the signal lines SGL1, SGL2, . . . , and SGLmin the state of being given the display data P1, P2, . . . , and Pm ofone horizontal scanning period 1H immediately before the stop periodTR_k+1, during the stop period TR_k+1. This holds the respectivesub-pixels SPix coupled to the signal lines SGL1, SGL2, . . . , and SGLmin the state in which the display data P1, P2, . . . , and Pm of onehorizontal scanning period 1H immediately before the stop period TR_k+1are written therein.

The stop control according to the second modification can substantiallyequalize the potential changes in the signal lines SGL immediately afterthe transition from the stop period TR_k+1 to the display period TI_k+2to the potential changes in the signal lines SGL during the displayperiod TI before the stop period TR. This allows the display device 1 toreduce, for example, the streak defects or the unevenness generatedbetween the sub-pixels SPix in a row first selected immediately afterthe transition from the stop period TR_k+1 to the display period TI_k+2and the sub-pixels SPix of other rows. The stop control according to thesecond modification does not require the division of the stop periodTR_k+1 into the former and the latter terms, thus eliminating the needfor securing the latter term of the stop period TR_k+1. This allows thestop control according to the second modification to limit the stopperiod TR_k+1 to the necessary minimum.

While turning off the switches SW1, SW2, . . . , and SWm sets the signallines SGL1, SGL2, . . . , and SGLm coupled thereto to have the highimpedance during the stop period TR_k+1, the signal lines SGL1, SGL2, .. . , and SGLm have relatively large components Cc, Cg, and Ct of theelectrostatic capacitance. In addition, the common electrodes COMLillustrated in FIG. 2, for example, face the signal lines SGL1, SGL2,and SGLm, and thus play a role of shielding against electromagnetism.This gives the signal lines SGL1, SGL2, . . . , and SGLm relatively highresistance to disturbance noise. Cc is the electrostatic capacitancebetween the signal lines and the common electrodes COML; Cg is theelectrostatic capacitance at portions where the signal lines SGLintersect the scan lines GCL; and Ct is the electrostatic capacitancebetween the signal lines SGL and the TFT elements Tr included in thesub-pixels SPix. Ct is the electrostatic capacitance when the TFTelements Tr are turned off.

As illustrated in FIG. 17, the COG 19 serving as the transmission sourceof the display data P is coupled with the switches SW1, SW2, . . . , andSWm by video lines VL serving as the wiring. Electrostatic capacitanceCv exists between the adjacent video lines VL, VL illustrated in FIG. 18mostly due to a fringe electric field formed between the adjacent videolines VL. As many as several hundreds to over one thousand of the videolines VL are arranged at the frames Gd of the liquid crystal displayunit 10 illustrated in FIG. 2. To contain the many video lines VL in thepredetermined frames Gd, the video lines VL have small line widths andsmall lengths. This results in a relatively small value of Cv. Thecommon electrodes COML do not face the video lines VL, and thus cannotbe expected to have an effect of shielding against electromagnetism. Asa result, during the stop period TR_k+1, the increasing impedance ofoutputs of amplifiers 19Bn, 19Bn+1, 19Bn+2, . . . included in the COG 19causes the video lines VL to be vulnerable to disturbance noise.

If the disturbance noise received during the stop period TR_k+1 givesany of the video lines VL an extremely high potential or an extremelylow potential, the potential of the video line VL may exceed a withstandvoltage between the source and the drain of any of the switches SW1,SW2, . . . , and SWm. If the process enters the display period TI_k+2,and the respective video lines VL are coupled to the amplifiers 19Bn,19Bn+1, 19Bn+2, . . . included in the COG 19 while any of the videolines VL has an extremely high potential or an extremely low potential,the potential of the video line VL may exceed a withstand voltage of anyof the amplifiers 19Bn, 19Bn+1, 19Bn+2, . . . of the COG 19.

When performing the stop control according to the second modification,the control unit 11 turns off all of the switches SW1, SW2, . . . , andSWm and sets the video lines VL from the COG 19 to the switches SW1,SW2, . . . and SWm illustrated in FIG. 17 to have any desirablepotential during the stop period TR_k+1. Controlling in this way canreduce the possibility that the potential of any of the video lines VLexceeds the withstand voltage between the source and the drain of any ofthe switches SW1, SW2, . . . , and SWm, or the withstand voltage of anyof the amplifiers 19Bn, 19Bn+1, 19Bn+2, . . . of the COG 19. A procedureof the stop control according to the second modification will be brieflydescribed.

FIG. 19 is a flowchart illustrating the procedure of the stop controlaccording to the first modification. Steps S301 and S302 of the stopcontrol according to the second modification are the same as Steps S101and S102 of the above-described stop control, and thus descriptionthereof will not be repeated. If the process is in the stop periodTR_k+1 (Yes at Step S302), the control unit 11 turns off all of theswitches SW1, SW2, . . . , and SWm and supplies all of the video linesVL with any desirable potential via the COG 19 at Step S303. If theprocess is not in the stop period TR_k+1 (No at Step S302), the controlunit 11 returns to the start and performs the processes from Step S301.Performing these processes allows the control unit 11 to reduce, forexample, the streak defects or the unevenness generated in the displayarea Ad of the liquid crystal display unit 10 of the display device 1.In addition, it becomes less possible that the potential of any of thevideo lines VL exceeds the above-mentioned withstand voltage, so thatdeterioration in durability of the source selector 13S illustrated inFIG. 6 and the COG 19 illustrated in FIG. 17 is suppressed.

1-2. Display Device with Touch Detection Function

In the present embodiment and the modifications thereof, the displaydevice 1 may have a function other than the display function. Adescription will be made below of a display device with a touchdetection function that has a touch detection function. The displaydevice with the touch detection function performs driving for detectinga touch during the stop period TR.

FIG. 20 is a diagram illustrating an example of the display device withthe touch detection function. This display device with the touchdetection function 1 a in the present embodiment detects a touch byusing capacitative type touch detection. As illustrated in FIG. 20, thedisplay device with the touch detection function 1 a includes the liquidcrystal display unit 10 and a touch detection device 20. The touchdetection device 20 in the present example uses the common electrodesCOML of the liquid crystal display unit 10 also as drive electrodesCOMD. However, the drive electrodes COMD are not limited to such a type.Drive electrode scanning units 14A and 14B for driving the driveelectrodes COMD are formed on the TFT substrate 21. As illustrated inFIG. 20, drive electrode blocks B of the drive electrodes COMD and touchdetection electrodes TDL are arranged to cross each otherthree-dimensionally in a separate manner in the direction orthogonal tothe surface of the TFT substrate 21.

The drive electrodes COMD have a shape divided into a plurality ofstripe-like electrode patterns extending in one direction. When thetouch detection operation is performed, the drive electrode scanningunits 14A and 14B sequentially feed touch driving signals VcomAC to therespective electrode patterns of the drive electrodes COMD. The driveelectrodes COMD of each of the stripe-like electrode patterns aresimultaneously supplied with the touch driving signals VcomAC, and thestripe-like electrode patterns serve as the drive electrode blocks Billustrated in FIG. 20. The drive electrode blocks B (drive electrodesCOMD) are formed in a direction along one side of the touch detectiondevice 20, and the touch detection electrodes TDL are formed in adirection along another side of the touch detection device 20. Outputsof the touch detection electrodes TDL are provided, for example, on theabove-mentioned one side of the touch detection device 20, and coupledvia the flexible printed circuit board T to a touch detection unit 40that is mounted on the flexible printed circuit board T. In this manner,the touch detection unit 40 is mounted on the flexible printed circuitboard T, and coupled with each of the parallel-arranged touch detectionelectrodes TDL. The flexible printed circuit board T only needs to be aterminal, and is not limited to be a flexible printed circuit board. Inthis case, the touch detection unit 40 is provided outside the displaydevice with the touch detection function 1 a.

A drive signal generating unit for generating the touch driving signalsVcomAC is embedded in the COG 19. The drive electrode scanning units 14Aand 14B are disposed at the frames Gd, respectively. The drive electrodescanning units 14A and 14B are formed using TFT elements on the TFTsubstrate 21. The drive electrode scanning units 14A and 14B aresupplied with the display driving voltage VCOM from the above-mentioneddrive signal generating unit via the display wiring LDC, and suppliedwith the touch driving signals VcomAC via touch wiring LAC. The driveelectrode scanning units 14A and 14B each occupy a certain width Gdv atthe corresponding frame Gd. The drive electrode scanning units 14A and14B can drive each of the parallel-arranged drive electrode blocks Bfrom both sides. The display wiring LDC for feeding the display drivingvoltage VCOM and the touch wiring LAC for feeding the touch drivingsignals VcomAC are arranged parallel to each other at the frames Gd. Thedisplay wiring LDC is arranged on the side nearer to the display area Adthan the touch wiring LAC. This structure causes the display drivingvoltage VCOM fed by the display wiring LDC to stabilize potential statesat ends of the display area Ad. This stabilizes the display particularlyon the liquid crystal display unit using the liquid crystals of thehorizontal electric field mode.

Basic Principle of Capacitative Type Touch Detection

FIG. 21 is an explanatory diagram for explaining a basic principle ofthe capacitative type touch detection, the diagram illustrating a statein which a finger is neither in contact with nor in proximity to adevice. FIG. 22 is an explanatory diagram illustrating an example of anequivalent circuit in the state illustrated in FIG. 21 in which thefinger is neither in contact with nor in proximity to a device. FIG. 23is an explanatory diagram for explaining the basic principle of thecapacitative type touch detection, the diagram illustrating a state inwhich the finger is in contact with or in proximity to a device. FIG. 24is an explanatory diagram illustrating an example of the equivalentcircuit in the state illustrated in FIG. 23 in which the finger is incontact with or in proximity to a device. FIG. 25 is a diagramillustrating an example of waveforms of a drive signal and a touchdetection signal.

The touch detection device 20 illustrated in FIG. 20 operates based onthe basic principle of the capacitative type touch detection, andoutputs a touch detection signal Vdet. For example, as illustrated inFIG. 21, a capacitive element C1 includes a pair of electrodes, that is,a drive electrode E1 and a touch detection electrode E2 that arearranged facing each other with a dielectric body D interposedtherebetween. As illustrated in FIG. 22, the capacitive element C1 iscoupled, at one end thereof, to an alternating signal source (drivesignal source) S, and coupled, at the other end thereof, to a voltagedetector (touch detection unit) DET. The voltage detector DET is, forexample, an integration circuit included in the touch detection unit 40illustrated in FIG. 20.

Applying an alternating-current rectangular wave Sg having apredetermined frequency (such as approximately several kilohertz toseveral hundred kilohertz) from the alternating signal source S to thedrive electrode E1 (one end of the capacitive element C1) causes anoutput waveform (touch detection signal Vdet) to occur via the voltagedetector DET coupled to the side of the touch detection electrode E2(the other end of the capacitive element C1). The alternating-currentrectangular wave Sg corresponds to the touch driving signals VcomAC.

In the state (non-contact state) in which the finger is neither incontact with (nor in proximity to) a device, a current I₀ according tothe capacitance value of the capacitive element C1 flows in associationwith the charge and discharge of the capacitive element C1, asillustrated in FIGS. 21 and 22. As illustrated in FIG. 25, the voltagedetector DET converts a variation in the current I₀ according to thealternating-current rectangular wave Sg into a variation in a voltage(waveform V₀ of a solid line).

In the state (contact state) in which the finger is in contact with (orin proximity to) a device, electrostatic capacitance C2 produced by thefinger exists in contact with or in proximity to the touch detectionelectrode E2, as illustrated in FIG. 23. Thus, a fringe component of theelectrostatic capacitance existing between the drive electrode E1 andthe touch detection electrode E2 is interrupted, and the electrostaticcapacitance acts as a capacitive element C1′ having a smallercapacitance value than that of the capacitive element C1. With referenceto the equivalent circuit illustrated in FIG. 24, a current I₁ flows inthe capacitive element C1′. As illustrated in FIG. 25, the voltagedetector DET converts a variation in the current I₁ according to thealternating-current rectangular wave Sg into a variation in a voltage(waveform V₁ of a dotted line). In this case, the waveform V₁ has asmaller amplitude than that of the above-mentioned waveform V₀. Thisshows that the absolute value |ΔV| of a voltage difference between thewaveform V₀ and the waveform V₁ changes according to an influence of anobject, such as a finger, approaching from the outside. To accuratelydetect the absolute value |ΔV| of the voltage difference between thewaveform V₀ and the waveform V₁, the voltage detector DET preferablyperforms an operation including a period Reset during which the chargeor discharge of the capacitor is reset by switching in the circuit inaccordance with the frequency of the alternating-current rectangularwave Sg.

The touch detection device 20 illustrated in FIG. 20 is configured toperform the touch detection by sequentially scanning one detection blockat a time according to the touch driving signals VcomAC fed from thedrive electrode scanning units 14A and 14B. The touch detection device20 is configured to output the touch detection signals Vdet from thetouch detection electrodes TDL via the voltage detectors DET illustratedin FIGS. 22 and 24 on a detection block basis, and transmit the touchdetection signals Vdet to the touch detection unit 40.

The touch detection unit 40 performs processing to extract only thedifference of signals due to the finger. The difference of signals dueto the finger has the absolute value |ΔV| of the difference between thewaveform V₀ and the waveform V₁ described above. The touch detectionunit 40 compares the difference of signals due to the finger with apredetermined threshold voltage, and if the difference is the thresholdvoltage or more, determines that the state is the contact state of anexternal proximate object. The touch detection unit 40 compares thedetected signal of the difference of signals due to the finger with thepredetermined threshold voltage, and if the difference is less than thethreshold voltage, determines that the state is the non-contact state ofan external proximate object. The touch detection unit 40 can performthe touch detection in this manner. The detection of the touch causesthe touch detection unit 40 to obtain touch panel coordinates of thetouch, and to output the touch panel coordinates as a signal outputVout.

While the description has been made above of the embodiments and themodifications thereof, the above description does not limit the presentdisclosure. The constituent elements of the embodiments and themodifications thereof described above include elements easily conceivedby those skilled in the art, substantially identical elements, andelements in the range of what are called equivalents. Theabove-described constituent elements can also be combined asappropriate. The constituent elements can be omitted, replaced, and/ormodified in various ways within the scope not deviating from the gist ofthe present disclosure.

2. Application Examples

With reference to FIGS. 26 to 38, a description will be made ofapplication examples of the display device 1 described in the embodimentand the modifications thereof. FIGS. 26 to 38 are diagrams eachillustrating an example of an electronic apparatus to which the displaydevice according to the present embodiment or any of the modificationsthereof is applied. The display device 1 according to the presentembodiment or the display device according to any of the modificationsthereof can be applied to electronic apparatuses in all fields, such astelevision devices, digital cameras, laptop computers, portableelectronic apparatuses including mobile phones, and video cameras. Inother words, the display device 1 according to the present embodiment orthe display device according to any of the modifications thereof can beapplied to electronic apparatuses in all fields that display externallyreceived video signals or internally generated video signals as imagesor video pictures.

Application Example 1

The electronic apparatus illustrated in FIG. 26 is a television deviceto which the display device 1 according to the present embodiment or thedisplay device according to any of the modifications thereof is applied.This television device includes, for example, a video display screenunit 510 that includes a front panel 511 and a filter glass 512. Thevideo display screen unit 510 corresponds to the display device 1according to the present embodiment or the display device according toany of the modifications thereof.

Application Example 2

The electronic apparatus illustrated in FIGS. 27 and 28 is a digitalcamera to which the display device 1 according to the present embodimentor the display device according to any of the modifications thereof isapplied. This digital camera includes, for example, a light-emittingunit 521 for flash, a display unit 522, a menu switch 523, and a shutterbutton 524. The display unit 522 corresponds to the display device 1according to the present embodiment or the display device according toany of the modifications thereof.

Application Example 3

The electronic apparatus illustrated in FIG. 29 represents an externalappearance of a video camera to which the display device 1 according tothe present embodiment or the display device according to any of themodifications thereof is applied. This video camera includes, forexample, a body 531, a lens 532 for taking a subject provided on thefront side face of the body 531, and a start/stop switch 533 forshooting, and a display unit 534. The display unit 534 corresponds tothe display device 1 according to the present embodiment or the displaydevice according to any of the modifications thereof.

Application Example 4

The electronic apparatus illustrated in FIG. 30 is a laptop computer towhich the display device 1 according to the present embodiment or thedisplay device according to any of the modifications thereof is applied.This laptop computer includes, for example, a body 541, a keyboard 542for input operation of characters, etc., and a display unit 543 thatdisplays images. The display unit 543 corresponds to the display device1 according to the present embodiment or the display device according toany of the modifications thereof.

Application Example 5

The electronic apparatus illustrated in FIGS. 31 to 37 is a mobile phoneto which the display device 1 according to the present embodiment or thedisplay device according to any of the modifications thereof is applied.This mobile phone is, for example, composed of an upper housing 551 anda lower housing 552 connected to each other by a connection unit (hingeunit) 553, and includes a display 554, a subdisplay 555, a picture light556, and a camera 557. The display 554 and/or the subdisplay 555correspond(s) to the display device 1 according to the presentembodiment or the display device according to any of the modificationsthereof.

Application Example 6

The electronic apparatus illustrated in FIG. 38 is a portableinformation terminal that operates as a portable computer, amultifunctional mobile phone, a portable computer with voice callcapability, or a portable computer with communication capability, andthat is sometimes called a smartphone or a tablet computer. Thisportable information terminal includes, for example, a display unit 562on a surface of a housing 561. The display unit 562 corresponds to thedisplay device 1 according to the present embodiment or the displaydevice according to any of the modifications thereof.

3. Aspects of Present Disclosure

The present disclosure includes aspects as follows.

(1) A display device that displays an image, the display devicecomprising:

a display area in which a plurality of pixels are aligned in row andcolumn directions, each of the pixels including a drive element;

a plurality of scan lines extending in the row direction, each of thescan lines being coupled with the drive elements included in the pixelsaligned in the row direction to transmit thereto a scan signal forselecting the pixels in the display area row by row;

a plurality of signal lines extending in the column direction, each ofthe signal lines being coupled with the drive elements included in thepixels aligned in the column direction to write display data of theimage to be displayed on the display area to the pixels in a rowselected by the scan signal; and

a display control unit configured to:

-   -   alternately repeat a display period of writing the display data        to the pixels and a stop period of stopping the writing of the        display data to the pixels;    -   in a former term of the stop period, set all of the signal lines        to have a predetermined potential; and    -   in a latter term of the stop period, provide the display data        written in the respective pixels in a row that has been selected        during the display period immediately before the stop period, to        the signal lines corresponding to the respective pixels.

(2) The display device according to (1), wherein, in the latter term ofthe stop period, the display control unit does not provide the displaydata to a signal line corresponding to a pixel to which the display datais written first among the pixels arranged in a row to be selected inthe display period following the stop period.

(3) The display device according to (1), wherein

the display control unit is configured to:

-   -   in the former term of the stop period, supply the signal lines        with, among pieces of the display data that has been written in        the respective pixels in the row that has been selected, a piece        of the display data that has been written in a second pixel        except a first pixel corresponding to a pixel to which the        display data is written first among the pixels arranged in a row        to be selected in the display period following the stop period;        and    -   in the latter term of the stop period, supply, among pieces of        the display data that has been written in the respective pixels        in the row that has been selected, each of pieces of the display        data except pieces of the display data that have been written in        the first and second pixels, to the signal line corresponding to        the pixel in which the piece of the display data has been        written.

(4) A display device that displays an image, the display devicecomprising:

a display area in which a plurality of pixels are aligned in row andcolumn directions, each of the pixels including a drive element;

a plurality of scan lines extending in the row direction, each of thescan lines being coupled with the drive elements included in the pixelsaligned in the row direction to transmit thereto a scan signal forselecting the pixels in the display area row by row;

a plurality of signal lines extending in the column direction, each ofthe signal lines being coupled with the drive elements included in thepixels aligned in the column direction to write display data of theimage to be displayed on the display area to the pixels in a rowselected by the scan signal;

switches provided between a transmission source of the display data andthe signal lines; and

a display control unit configured to:

-   -   alternately repeat a display period of writing the display data        to the pixels and a stop period of stopping the writing of the        display data to the pixels; and    -   in the stop period, turn off all of the switches and set wiring        from the transmission source to the switches to have any        desirable potential.

(5) An electronic apparatus comprising the display device according toaccording to any one of (1) to (4).

The electronic apparatus of the present disclosure includes theabove-described display device. Examples of the electronic apparatus ofthe present disclosure include, but are not limited to, a televisiondevice, a digital camera, a personal computer, a video camera, and aportable electronic apparatus such as a mobile phone.

The present disclosure can reduce streak defects and unevenness in animage displayed on a display device.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The invention is claimed as follows:
 1. A display device that displaysan image, the display device comprising: a display area in which aplurality of pixels are aligned in row and column directions, each ofthe pixels including a drive element; a plurality of scan linesextending in the row direction, each of the scan lines being coupledwith the drive elements included in the pixels aligned in the rowdirection to transmit thereto a scan signal for selecting the pixels inthe display area row by row; a plurality of signal lines extending inthe column direction, each of the signal lines being coupled with thedrive elements included in the pixels aligned in the column direction towrite display data of the image to be displayed on the display area tothe pixels in a row selected by the scan signal; and a display controlunit configured to: in the former term of the stop period, supply thesignal lines with, among pieces of the display data that has beenwritten in the respective pixels in the row that has been selected, apiece of the display data that has been written in a second pixel excepta first pixel corresponding to a pixel to which the display data iswritten first among the pixels arranged in a row to be selected in thedisplay period following the stop period; and in the latter term of thestop period, supply, among pieces of the display data that has beenwritten in the respective pixels in the row that has been selected, eachof pieces of the display data except pieces of the display data thathave been written in the first and second pixels, to the signal linecorresponding to the pixel in which the piece of the display data hasbeen written.
 2. An electronic apparatus comprising the display deviceaccording to claim 1.